1. Field of the Disclosure
The present disclosure relates generally to toner cartridges used in electrophotographic image forming devices and, more particularly, to a toner cartridge having a shutter lock mechanism.
2. Description of the Related Art
In order to reduce the premature replacement of components traditionally housed within a toner cartridge for an image forming device, toner cartridge manufacturers have begun to separate components having a longer life from those having a shorter life into separate replaceable units. Relatively longer life components such as a developer roll, a toner adder roll, a doctor blade and a photoconductive drum are positioned in one replaceable unit (an “imaging unit”). The image forming device's toner supply, which is consumed relatively quickly in comparison with the components housed in the imaging unit, is provided in a reservoir in a separate replaceable unit in the form of a toner cartridge that mates with the imaging unit. In this configuration, the number of components housed in the toner cartridge is reduced in comparison with traditional toner cartridges. As a result, in systems utilizing a separate toner cartridge and imaging unit, the toner cartridge is often referred to as a “toner bottle” even though the toner cartridge is more complex than a mere bottle for holding toner.
To deliver toner from the toner cartridge to the imaging unit, an auger in the toner cartridge may be used to feed toner from an exit port on the toner cartridge into an entrance port on the imaging unit and into a second auger that disperses the toner within the imaging unit. As the toner is drawn out of the toner cartridge, it is augured through a shutter used for sealing the exit port of the toner cartridge when it is not inserted in the printer. In order to prevent the undesired release of toner, the shutter preferably remains closed unless the toner cartridge is installed in the image forming device. Accordingly, the shutter may be biased toward the closed position. As the toner cartridge reaches its final position in the image forming device, a pin or other type of projection on the image forming device may engage a catch on the toner cartridge and supply an opposing force to open the shutter. For example, U.S. Pat. No. 7,606,520, entitled “Shutter for a Toner Cartridge for use with an Image Forming Device” and assigned to the assignee of the present invention provides an example shutter mechanism.
A problem may be experienced if a user accidentally releases toner from the cartridge by inadvertently actuating the shutter or by intentionally engaging the shutter catch without appreciating its purpose until it is too late. The released toner may fall from the toner cartridge and contact an area surrounding the image forming device or a user's clothing resulting in uncleanliness. Image forming devices having a separate toner cartridge and imaging unit present an additional concern. If the imaging unit is not present when the toner cartridge is installed in the image forming device and the cartridge's shutter is opened by the image forming device, any toner exiting the shutter will leak from the cartridge's exit port into the interior of the image forming device because the imaging unit is not there to receive it. When leaked toner falls into the internal portions of the image forming device, it can cause reliability issues and, in some cases, print defects. Accordingly, it will be appreciated that a mechanism that prevents the unwanted release of toner from the cartridge's shutter is desired.